When an air conditioner in a vehicle is operating, a user may adjust the vanes in an air outlet assembly to direct an airflow toward to a desired direction. Conventional technologies usually employ a linkage structure to move vanes to change their direction. However, the linkage structure is visible through the gap of the vanes, which affects the appearance of the air outlet assembly and can obstruct the airflow. For example, a ventilation louver assembly or the air outlet assembly disclosed in the U.S. Pat. No. 5,520,579A comprises a lever connecting with the vanes to selectively direct an airflow from a vent. The lever pivotally connects at least one of vanes to concurrently move all the vanes to adjust their orientation. As the lever is disposed at the gaps among the vanes, an air flow area is reduced and the appearance of the air outlet assembly is adversely affected.